The present invention relates to a shredding apparatus, and more particularly to an automatically starting shredding apparatus.
A shredding machine is an essential machine in an office. Generally, two types of shredding apparatus are used. The first type results in elongated shredded paper, and the second type results in even smaller segmental shredded paper. FIG. 1 is a schematic top plane view of the first type of shredding apparatus. When paper to be shredded enters a channel 20, a trigger 22 disposed in the channel 20 in space between two cutters 211 is actuated to start the shredding operation, as described in U.S. Pat. No. 5,984,215. On the other hand, for the second type of shredding apparatus as shown in FIG. 2, the space between the two cutters 311 are filled with a spacer 32. In other words, there is no vacancy between the cutters 311 for the disposition of the trigger. Therefore, the trigger of the second type of shredding apparatus has to be arranged above the cutters in the channel.
FIG. 3 is a perspective diagram illustrating partial structures of a conventional shredding machine having an automatic paper-shredding start mechanism. As shown in FIG. 1, the shredding machine includes a first and second series of cutters 111 which are sleeved on a first shaft 11 and a second shaft 11xe2x80x2, respectively, a trigger 12, a carrying bar 13, an elastic plate 14, a gear set 15, a delay cam 151, a switch 16 and a motor 17. When paper passes through a channel 10 formed between the first and second shafts 11, 11xe2x80x2 and is cut by the cutters 111, the trigger 12 is simultaneously pushed by the paper and further carries the carrying bar 13 to rotate. Thus, a portion 131 of the carrying bar 13 is under a lifting position for being against the elastic plate 14 to turn on the switch 16, which starts the motor 17. Further, the first and second shafts 11, 11xe2x80x2 are driven to rotate by the motor 17 and enables the cutters 111 to cut the paper. The gear set 15 and the delay cam 151 are also driven to rotate by the motor 17. Thus, when the whole paper passes through the trigger 12 causing the trigger 12 not to be against by the paper, and not to further keep the portion 131 of the carrying bar 13 at the lifting position, the existence of the delay cam 151 allows the carrying bar to remain continuously against the elastic plate 14 for a while so as to keep the switch 16 on. Thus, the motor 17 can continuously operate for a delay time to assure that the paper is fully cut before the motor 17 stops.
For this automatic start mechanism, a long carrying bar is used for power transmission from the trigger to the switch via the elastic plate. As known, the carrying bar, once deformed, cannot lift the elastic plate normally to conduct the switch when paper is passing through the channel. Thus, the automatic start paper shredding function is invalid.
Therefore, the purpose of the present invention is to develop a shredding apparatus having an improved automatic start mechanism to deal with the above situations encountered in the prior art.
It is therefore an object of the present invention to provide a shredding apparatus which has a relatively small power transmission distance between the trigger and the switch so as to minimize the deformation effect of the carrying bar on the conduction of the switch.
According to an aspect of the present invention, there is provided a shredding apparatus having an automatic start mechanism. The shredding apparatus includes a channel for a paper to enter the shredding apparatus, a shredding mechanism for cutting the paper when the paper passes through the channel, a power source for providing a motive power for the shredding mechanism, a trigger disposed in the channel for arising a move in response to a sustaining force of the paper against the trigger, a delay unit driven by the power source for delaying the sustaining force for a particular time, a lever connected between the trigger and the delay unit and transmitted by the trigger and the delay unit, and a switch electrically connected to the power source and optionally connected to a first portion of the lever depending on a moving status of the lever to be switched between an ON condition and an OFF condition, wherein a distance between the first portion of the lever and the trigger is smaller than a distance between the delay unit and the trigger.
For example, the power source is an electric motor.
Preferably, the shredding mechanism includes a first shaft carried to rotate by the power source, a second shaft disposed with the first shaft in parallel and carried to rotate by the power source, a plurality of cutters staggeredly sleeved and fixed on the first and second shafts and transmitted to rotate by the first and second shaft, respectively, for cutting the paper when the paper passes through the channel, wherein a space is existent between every two adjacent cutters on the same shaft, and a plurality of guiding plates, each of which is disposed in one the space, and movably sleeved on one of the first and the second shafts.
Preferably, the channel includes an entrance end for putting the paper thereinto. The trigger preferably includes a protruding element fixed on the lever, disposed at the entrance of the channel, and against by the paper when the paper passes through the channel to carry the lever to rotate.
Preferably, the delay unit includes a delay gear set connected to the power source and carried by the power source to rotate, and a delay cam connected to the delay gear set and the lever and carried by the delay gear set to rotate for delaying the sustaining force for the particular time.
Preferably, the first portion of the lever is a protrusion optionally connected with the switch for switching the switch between the ON condition and OFF condition depending on a connection status between the protrusion and the switch.
The present invention may best be understood through the following description with reference to the accompanying drawings, in which: